diff options
Diffstat (limited to 'net/ipv4/route.c')
| -rw-r--r-- | net/ipv4/route.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 0a843ef2b709..3dee0043117e 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -603,11 +603,13 @@ static void fnhe_flush_routes(struct fib_nh_exception *fnhe) rt = rcu_dereference(fnhe->fnhe_rth_input); if (rt) { RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); + dst_release(&rt->dst); rt_free(rt); } rt = rcu_dereference(fnhe->fnhe_rth_output); if (rt) { RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); + dst_release(&rt->dst); rt_free(rt); } } @@ -1332,9 +1334,12 @@ static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, rt->rt_gateway = daddr; if (!(rt->dst.flags & DST_NOCACHE)) { + dst_hold(&rt->dst); rcu_assign_pointer(*porig, rt); - if (orig) + if (orig) { + dst_release(&orig->dst); rt_free(orig); + } ret = true; } @@ -1357,12 +1362,20 @@ static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) } orig = *p; + /* hold dst before doing cmpxchg() to avoid race condition + * on this dst + */ + dst_hold(&rt->dst); prev = cmpxchg(p, orig, rt); if (prev == orig) { - if (orig) + if (orig) { + dst_release(&orig->dst); rt_free(orig); - } else + } + } else { + dst_release(&rt->dst); ret = false; + } return ret; } |